Combination draft-furnace.



No. 709,|74. Patented Sept. l6, I902.

0. D. UBVIS.

COMBINATIONDBAFT FURNACE. (Application filcd my 18,1901. leneizqed July 29, 1902.)

(No Model.)

ij v 'Q I mvamom fle 3- WITNESSES:

ATTORNEY No. 709,04. Patented Sept. l6, I902}.

0. n. ORVIS. COMBINATION DRAFT FURNACE.

(Application fllod May 18, 1901. Renewed July 29, 1902.) (No Model.) 3 Sheets-Sheet 2.

WITNESSES ,INVENTORI 10m. @Ma

ATTORNEY, I

ms Ps'rsas co. moruumo WASNINGTON. 0. c4

No. 709,!74. V Pa tented Sept. 16, 1902.

0. D. URVIS. comsmumn DRAFT FURNACE.

3 Shee ts-Sheet 3.

(No Model.)

wnmsssas:

ATTORNEY UNITED STATES OREL D. ORVIS, OF NEW YORK, N. Y.

COMBINATION DRAFT-FURNACE.

SPECIFICATION forming part Of Letters Patent No. 709,174, dated September 16, 1902.

Application filed May 13, 1901. Renewed July 29, 1902. Serial No. 117,534. (No model.)

To all whom it may concern: 7

Be it known that I, OREL D. ORVIS, a citizenof the United States of America, residing at the borough of Manhattan, New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Combination Draft-Furnaces,of which the following is a specification.

My invention has reference to improvements in furnaces, and particularly to a combination draft-furnace especially adapted for steam-boilers, and has for its objects, first,

to obtain a more efficient combustion of the fuel on the grate; secondly, a better circulation of Water through the water-grate than heretofore, and, thirdly, to provide a firespace which will not take up more head room than the ordinary grate.

To this end my invention consists, essentially, in a combination draft-furnace having a water-grate, a fire-chamber located above said grate and including part of the boilersurface, means for establishing a circulation of water through the grate, lateral exits for the products of combustion, downward exits for the products of combustion, rear exits fol-the products of combustion, a lower grate adapted to receive the droppings from the first grate, and'a rear and upward exit for the products of combustion from said grate, all said parts being arranged to cause a commingling of the gases from the water-grate and the lower grate.

The nature of my invention will best be understood when described in connection with the accompanying drawings,in which Figure-1 represents a vertical section of a steam-boiler furnace embodying my invention, the plane of section being taken on the line 1 1, Fig. 2. Fig. 2 is a vertical section on the line 2 2, Fig. 1. Fig. 3 is a vertical section on the line 3 3, Fig. 1. Fig. 4. is a section on the line 4. 4, Fig. 2, part being broken away. Fig. 5 is a horizontal section on the line 5 5, Fig. 1.

Similarletters and numerals of reference designate corresponding parts throughout the several views of the drawings.

In the example illustrated I have shown my invention applied to an ordinary return tubular boiler A, having a usual setting consisting of side walls B B, a front wall 0, and

header F, said headers being respectively supported by the front wall G of the furnace and by a bridge-wall G. The headers are provided with central transverse partitions 2, dividing them into two chambers each, and the front header is also provided with upward extensions at each end, which are connected by horizontal tubes 3 5, vertical tubes 4 4, and suitable fittings with the water or steam space of the boiler, as best seen in Figs. 1 and 3. The chambers formed in the rear header F by the transverse partition 2 are connected by horizontal tubes 5 5, vertical tubes 6 6, and suitable fittings with the water-space of the boiler below the level of the connection of the tubes 3 4, previously referred to.

Upon the tubes 3 3 are supported converging arches H H, which are directed toward the center of the boiler and form, with the same and a rear wall it, a closed fire-chamber, from which the products of combustion are in part drawn downwardly and rearwardly through the water-grate by the furn ace-draft, as indicated by arrows 10, the other part passing laterally between the grate and the tubes 3 and laterally and downwardly through the grate, and thence rearwardly between the grate and the walls of the furnace. For the purpose of obtaining a better combustion of the laterally-issuing gases I provide the side walls B of the furnace with recesses 7 adjacent to the sides of the water-grate and extending throughout the length of the arches H, these recesses forming small combustionchambers. Toprevent increased. radiation, in view of the diminution of the thickness of the walls at these parts I preferably line the outer walls of the said recesses with asbestos or other suitable material 8. Above the recesses and extending inwardly toward the arches II are placed deflecting-plates 9, adapted to direct the flow of gas inwardly toward the boiler. These plates extend throughout the length of the arches or may be longer'than the latter. Below the water-grate E is located an ordinary grate J, which receives the droppings from the upper grate. The products of combustion of these droppings are carried rearwardly and upwardly, as indicated by arrows 11, and mix with the products of combustion from the upper grate just in front of the bridge-wall, thus producing an increased combustion at this point and causing heating above and just beyond the bridge-wall, as in the ordinary updraft-furnace.

It will be readily understood from the foregoing description that the construction of the furnace induces three distinct drafts or currents of the products of combustion-to wit, first, a downward and rearward draftthrough the grate; secondly, lateral and rearward drafts from above and through the grate, and, thirdly, an upward and rearward draft from the lower grate.

Tubes 3 3 are connected by a transverse horizontal tube 12, located just below the'rear wall h, which is preferably connected with a vertical central tube 13 with the bottom of the boiler, so as to insure circulation. This tube permits the flame or products of combustion to pass downwardly and rearwardly from the incandescent bed of fuel and limits the grate-surface, the coal not passing back of the same, and consequently protects the rear wall from the usual implements employed in raking and cleaning the grate. The circulation of water takes place downwardly through the tubes 6 6, through the tubes 5 5, thence through the tubes of the water-grate on one side of the partitions 2 in the direction of arrows 14, thence rearwardly through the tubes 3, as indicated by arrows 14, back to the boiler.

It is to be understood that the lower grate which receives the droppings could be omitted without afiecting the practical operation of the furnace, although its use increases the efficiency of the same.

' What I claim as new is- 1. In acombination draft-furnace, the combination with awater-grate, of a fire-chamber located above said grate and including part of the boiler-surface, and means for establishing a circulation of water through the grate; said grate having lateral exits for the products of combustion, downward exits for the products of combustion, and rear exits for the products of combustion; all said parts being arranged to cause a commingling of the gases, substantially as described.

2. Ina combination draft-furnace,the combination with a water-grate, of a fire-chamber located above said grate and including part of the boiler-surface, and means for establishing a circulation of water through the grate; said grate having lateral exits for the products of combustion, downward exits for the products of combustion, rear exits for the products of combustion,alower grate adapted to receive the droppings from the first grate, and a rear and upward exit for the products of combustion from said grate; all said parts being arranged to cause a commingling of the gases from the water-grate and the lower grate, substantially as described.

3. In a combination draft-furnace,the combination with a water-grate, of a fire-chamber located above said grate, and means for establishing a circulation of water through the grate; said grate having lateral exits for the products of combustion, downward exits for the products of combustion, and rear exits for the products of combustion; all said parts being arranged to cause a com mingling of the gases, substantially as described.

4. In a combination draft-furnace,the combination with a water-grate, of a fire-chamber located above said grate, and means for establishing a circulation of water through the grate; said grate having lateral exits for the products of combustion, downward exits-for the products of combustion, rear exits for the products of combustion, a lower grate adapted to receive the droppings from the first grate, and a rear and upward exit for the products of combustion from said grate; all said parts being arranged to cause a commingling ot' the gases from the water-grate and the lower grate, substantially as described.

5. In a furnace,the combination with a firechamber havinga water-grate, of converging arches extending from said grate and abutting against the boiler and exposing part of the boiler to radiant heat, combined with means for establishing a circulation of water through the grate, a lower grate adapted to receive the droppings from the first grate, a bridge-wall, and a wall closing the rear of the arches, all arranged to cause a commingling of the gases from the Water-grate and the lower grate between the arches and the bridge-wall, substantially as described.

6. In a furnace, the combination with a firechamber having a water-grate opening laterally and furnace-walls having formed therein on each side of and adjacent to the grate a series of combustion-chambers into which the products of combustion from the grate pass in their rearward passage under the influence of the draft, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

OREL D. ORVIS. Witnesses:

EUGENIE P. HENDRICKSON, WILLIAM J. CAMPBELL. 

